The present invention is directed to machining, in particular, to machining drum or tube blanks to be used for electrophotographic and ionographic imaging members. The present invention is also directed to an apparatus for securing a workpiece on a mandrel.
Ionographic and electrophotographic imaging members may be provided in a number of forms. One form comprises a rigid supporting drum on which the imaging layer or layers are mounted. In some applications, for example, in liquid ink processes and ionographic processes, the drum has stringent specifications for straightness, taper, and run-out error. It is therefore necessary to provide a method for manufacturing large, very straight drum blanks having minimal radial run-out error and low unit manufacturing cost.
One process for producing drum blanks uses a diamond lathe to machine the surface of the drum blank. Although diamond lathe facilities provide good results, it is difficult to mount the drum blanks during machining. The chucking or holding process used to support the drum blank during machining tends to non-uniformly stress the drum during the turning cycle. When the holding forces are released, the drum relaxes, tending to adversely affect the straightness of the drum blank.
It is known to secure different types of components for machining. One apparatus for securing turbine blades is disclosed in U.S. Pat. No. 4,822,013 to Johnson. In this apparatus, a casing is provided which is filled with location material for securing the component. The location material preferably has a high resistance to extrusion and acts to locate the component during machining.
Another process for fixing parts for machining is disclosed in Soviet Patent No. 1,115,880. The process comprises pouring a fluid such as water into a cavity having a deformable tube inserted therein. The fluid solidifies when cooled. Expansion of the solidifying fluid is compensated for by the tube, allowing for a more precise fixing of parts for machining.
Although the above-described devices are advantageous for fixing particular components for machining, there continues to be a need for fixing and mounting drum blanks for electrophotographic and ionographic applications.